Centering point for lathes, grinding machines, and the like



FOR LATH-ES NDING HINES AND THE LI Filed Jan. 20, 1947 1951 A. ENDERHA2,564,256

CENTERINSAgOI 8 Alberta M. Henderhan QM 406. WW m Attorneys PatentedAug. 14, 1951 UNITED STATES PATENT OFFICE CENTERING POINT FOR LATHES,GRINDING MACHINES, AND THE LIKE Alberta M. Henderhan, Sunland, Calif.

Application January 20, 1947, Serial No. 723,071

2 Claims. (01. 82 -33) The present invention relates to new and usefulimprovements in lathe centers for locating and supporting the center ofthe work in a lathe, grinding machine, or other types of machines whereit is necessary to support the work at its true center while grinding orperforming other types of operation on the work.

An important object of the invention is to provide alocating center ofthis character embodyin means for locating and supporting the center ofthe work in the machine and including an anti-friction abutment carriedby the center for one end of the work.

A further object of the invention is to provide an attachment of thischaracter of simple construction, which is efiicient and reliable inuse, relatively inexpensive to manufacture and otherwise well adaptedfor the purposes for which the same is intended.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, and in which:

Figure l is a side elevational view of a grinding machine showing thelocating center mounted therein and with parts broken away and shown insection.

Figure 2 is an enlarged longitudinal sectional view of the locatingcenter.

Figure 3 is a transverse sectional view taken on a line 3-3 of Figure 2,and

Figure 4 is an enlarged perspective view of the centering pin;

Referring now to the drawing in detail Wherein for the purpose ofillustration I have disclosed a preferred embodiment of the inventionthe numeral 5 designates a shank tapering toward its inner end andformed with a longitudinally extending bore 6. A cetering pin 1 isslidably mounted in the front end of the bore, the front end of the pinbeing tapered as shown at 8 to form a point 9 at its outer end.

, A coil spring I is positioned in the bore 6 behind the pin, the rearend of the spring abutting a washer ll slidably mounted in the bore andengaged by an adjusting screw I2 threaded in the rear end of the bore toregulate the tension of the spring i0.

The pin 1 is formed with a longitudinally extending groove l3, the baseof the groove having recesses M at each end thereof.

A screw I is threaded through one side of the shank 5 to position itsinner end in the groove I3 to secure the pin 1 against rotary movement.The screw I5 is formed with a threaded bore IS in which a locking screwI1 is threaded to project inwardly of the screw l5 for entering eitherthe front or rear recess id to lock the pin against longitudinalmovement in either an inwardly retracted position in the shank 5 or inan outwardly projected position.

A cap 18 is threaded over the outer end of the shank 5 in the outer endof which a ball bearing assembly I9 is mounted having a sleeve 20supported centrally thereof and through which the outer end of the pin 1is movable into and out of its projected position. The outer end of thesleeve 20 is formed with a flan e 2| overlying the bearing assembly andprojecting forwardly of the front end of the cap l8 and shank 5 as shownmore clearly in Figure 2 of the drawing.

In the operation of the device the shank 5 is mounted in the work head2| of a grinding machine with the front end of the centering attachmentprojecting outwardly of the work head as shown in Figure 1. The pointedend 9 of pin 1 is projected outwardly by the spring III to engage acenter recess (not shown) at one side or end of the work 22, the otherside or end of the work being supported in the tailstock 23 of the ma--chine. As the work is changed into the machine the pin 1 is retracted inthe shank 5 and the Work bears against the flange 2| of the sleeve 20for free rotation of the work after the latter has been properlycentered by the pin I. The work may then be machined or dressed in adesired manner by the grinding wheel 24,

In view of the foregoing description taken in conjunction with theaccompanying drawings it is believed that a clear understanding of thedevice will be quite apparent to those skilled in this art. A moredetailed description is accordingly deemed unnecessary. I

It is to be understood, however, that even though there is herein shownand described a preferred embodiment of the invention the same issusceptible to certain changes fully comprehended by the spirit of theinvention as herein described and the scope of the appended claims.

I claim: V

1. A center locator of the class described comprising a shank having abore, a spring biased pin slidably mounted in the bore to project fromone end thereof, said pin having a longitudinal groove and also havingrecesses spaced longitudinally from each other, a first locking screwthreaded transversely of the shank and engaged in the groove to preventrotation of the pin,

. a said first locking screw having an internal threaded bore, and asecond locking screw in the bore and selectively engageable in therecesses to secure the pin against sliding movement in its projected andretracted positions in the shank.

2. A center locator of the class described comprising a shank having abore, a spring biased pin slidably. mounted. in .the bore -to,= proj ectfrom one end thereof, said pin having *a 1ongitiidim tl groove and alsohaving recesses spaced longitudinally from each other, locking meansengaging in the groove to prevent rotation of the pin, and locking meansengageablelinlthezrecessesitoa secure the pin in a projected orretracte'd'po'sition in the shank, said first and second-namedlockingmeans comprising a first screw threaded transversely in the shank andtai secon'd lscre'w threaded longitudinally through the first screw.

ALBERTA M. HENDERHAN.

'4 REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 979,034 Rowe Dec. 20, 19101,912,987 Lovely June 6, 1933 "2,314,622 l'Klamp .Mar. 23, 19432,4631385 Holohan "Mar. 1, 1949 FOREIGN PATENTS Number -.Country Date$558312 France Aug. 25, 1923

